EPFL researchers have developed a 100% effective, ultra-thin active noise cancelling system that uses an ionized air plasma propulsion system instead of speakers. A 17mm (0.6 inch) thick layer can block 20 Hz noise as well as a 4m (13 ft) thick wall.
This is absolutely fascinating and the first I’ve ever heard of such tech. As a musician, I’m excited to see where this may go? Thanks for posting!